Spray nozzle assemblies are known, such as shown in U.S. Pat. No. 4,899,937 assigned to the same assignee as the present invention, which include a deflector flange that enhances particle breakdown and directs the spray pattern in a transverse direction. The deflector flange of the nozzle shown in the aforesaid United States patent is formed with a distinct recess or pocket in axial alignment with the liquid discharge orifice in the nozzle tip, which has been found to generate a spray pattern that has shallow bell-shaped liquid distribution curve with greatest quantities of liquid being directed in a central portion of the spray pattern and lesser quantities on opposite sides thereof so that overlapping spray patterns from a plurality of such nozzles mounted in laterally spaced relation to each other, such as on the boom on an agricultural sprayer, produce a substantially uniform distribution of liquid over the area being sprayed.
In hydraulic spraying applications, namely applications in which the liquid flow stream is not subject to air-assisted pre-atomization, such nozzles have been found to be susceptible to excessive wear that can alter the spray characteristics and substantially increase the liquid flow. Although wear is reduced if the liquid is pre-atomized by pressurized air prior to direction through the nozzle spray tip, such air assisted spraying generates a fog-like discharge of relatively fine liquid particles. In agricultural applications, unless such discharging spray is directed in a substantially straight downward direction, the fine liquid particles are subject to undesirable drift. Heretofore, it often has not been possible to easily mount such spray nozzles for straight downwardly directed spraying, particularly on booms which are adapted for vertical spray nozzle mounting. Since the deflector flange of the nozzle is disposed transversely to the discharge orifice, such nozzles also have been susceptible to clogging by solid materials that might be included in the liquid being sprayed.